As toys for intellectual development of toddlers or children, self-assembly block toy sets including a plurality of blocks of various shapes that may be assembled to make any type of artifact are being widely used. Such a self-assembly block toy set allows a child to assemble an artifact of various shapes according to imagination, and may be repeatedly used, that is, disassembling the artifact and making another type of artifact, and the self-assembly block toy set helps brain activity and intellectual development of children by stimulating creativity and imaginative power of children. Blocks mostly have a connection member. The connection member may have various shapes according to an engaging structure or an assembling location.
In addition, connection members are provided in various shapes, and thus, children may assemble the blocks in various shapes or may assemble toys delicately. Toys of various shapes may be manufactured according to how to use which kinds of connection members, and imaginary power of the children may be improved.